Category Archives: General

Liquid Plasma vs FFP: Definitions

I’ll spend the next few days discussing plasma. This is an important component of any trauma center’s massive transfusion protocol (MTP). Coagulopathy is the enemy of any seriously injured patient, and this product is used to attempt to fix that problem.

And now there are two flavors available: liquid plasma and fresh frozen plasma. But there is often confusion when discussing these products, especially when there are really three flavors! Let’s review what they are exactly, how they are similar, and how they differ.

Fresh frozen plasma (FFP)
This is plasma that is separated from donated whole blood. It is generally frozen within 8 hours, and is called FFP. However, in some cases it may not be frozen for a few more hours (not to exceed 24 hours total) and in that case, is called FP24 or FP. It is functionally identical to FFP. But note that the first “F” is missing. Since it has gone beyond the 8 hour mark, it is no longer considered “fresh.” To be useful in your MTP, it must be thawed, and this takes 20-40 minutes, depending on technique.

Thawed plasma
Take a frozen unit of FFP or FP, thaw, and keep it in the refrigerator. Readily available, right? However, the clock begins ticking until this unit expires after 5 days. Many hospital blood banks keep this product available for the massive transfusion protocol, especially if other hospital services are busy enough to use it if it is getting close to expiration. Waste is bad, and expensive!

Liquid plasma (never frozen)
This is prepared by taking the plasma that was separated from the donated blood and putting it in the refrigerator, not the freezer. It’s shelf life is that of the unit of whole blood it was taken from (21 days), plus another 5, for a total of 26 days. This product used to be a rarity, but is becoming more common because of its longer shelf life compared to thawed plasma.

Finally, a word on plasma compatibility. ABO compatibility is still a concern, but Rh is not. There are no red cells in the plasma to carry any of the antigens. However, plasma is loaded with A and/or B antibodies based on the donor’s blood type. So the compatibility chart is reversed compared to what you are accustomed to when giving red cells.

Remember, you are delivering antibodies with plasma and not antigens. So a Type A donor will have only Type B antibodies floating around in their plasma. This makes it incompatible with people with blood types B or AB.

Type O red cells are the universal donor type because the cells have no antigens on the surface. Since Type AB donors have both antigens on their red cells, they have no antibodies in their plasma. This makes AB plasma is the universal donor type. Weird, huh? Here’s a compatibility chart for plasma.

Next time, I’ll discuss the virtues of the various types of plasma when used for massive transfusion in trauma.

Vascular Trauma Resources At Pediatric Trauma Centers

There are two types of pediatric trauma centers: freestanding and combined. These adjectives refer to whether an adult trauma center is directly associated with the pediatric one. Over the years, I have come to appreciate that there may be substantial resource and experience differences between the two.

Trauma surgeons at freestanding centers are usually pediatric surgeons. They have managed trauma cases during their surgical residency and pediatric surgical fellowship, but usually have not taken a trauma fellowship. Their experience with complex trauma and advanced concepts like damage control surgery generally comes from their training and on the job experience. Surgeons at combined centers may be pediatric trained, or may be adult surgeons with pediatric experience. The adult surgeons are generally well-versed in advanced trauma concepts, and the pediatric surgeons can take advantage of the adult surgeons’ expertise in advanced trauma cases.

Freestanding pediatric centers may have fewer resources in some key areas, such as fellowship trained specialists in vascular surgery, GI endoscopy, and interventional radiology. A recent study accepted for publication from the University of Arkansas examines differences in surgeon practice patterns and resource availability at freestanding vs combined centers.

Two surveys were sent to 85 pediatric trauma centers around the US. Roughly half were Level I, and half were freestanding. One was sent to 414 pediatric surgeons at those centers inquiring about practice patterns, and the other was sent to the trauma medical directors of each center asking about their resources.

Here are the factoids:

  • 50 of the 85 trauma centers responded, as did 176 of the 414 surgeons. 48% of trauma medical directors responded. These are reasonable response rates for questionnaires.
  • Adult surgeons covered pediatric trauma at 6% of Level I centers, and 33% of Level II
  • During pediatric surgical fellowship, 56% participated in management of vascular trauma, 25% was managed by vascular surgeons, and 19% had no experience
  • At 23% of freestanding centers, vascular surgeons were not always available, and a vascular surgeon was not listed on the call schedule 38% of the time
  • 27% of freestanding facilities indicated that endovascular and stent capabilities were not available, and 18% did not have interventional radiologists (IR) available within 30 minutes
  • All combined centers had vascular and endovascular capabilities, and IR was available within 30 minutes 92% of the time

Bottom line: This is an intriguing paper that looks at a few of the disparities between freestanding and combined pediatric trauma centers. Obviously, it is hampered by the survey format, but does provide some interesting information. The focus was on vascular resources, and shows several of the major differences between the two types of centers.

Fortunately, vascular trauma is relatively rare in the pediatric age group. But it is possible that a child presenting to a freestanding pediatric trauma center may be managed by a pediatric surgeon with little vascular experience, and assistance from a fellowship trained vascular surgeon and/or interventional radiologist may be unavailable.

This paper provides important information regarding resource disparities in pediatric trauma care. Ideally, this should be reviewed and remedied as the Resources for Optimal Care of the Injured Patient (Orange Book) evolves over the coming years.

Reference: Pediatric Vascular Trauma Practice Patterns and Resource Availability: A Survey of ACS-Designated Pediatric Trauma Centers. J Trauma, accepted for publication Jan 12, 2018.

The Trauma Professional’s Blog Is 8 Years Old!

Hey everyone! This blog turned 8 years old this week!

Stay tuned for some very interesting stuff this year. The Trauma MedEd newsletter will start cranking out regularly again later this month. I’m considering broadening the social media presence. There will be more stuff on YouTube. And lastly, could there be a book in the future? Stay tuned, and as always, your support and comments are welcome!

Michael

VTE Prophylaxis Before Spine Surgery?

Many surgeons and surgical subspecialists are nervous about operating on people who are taking anticoagulants. This seems obvious when it involves patients on therapeutic anticoagulation. But it is much less clear when we are talking about lower prophylactic doses.

Spine surgeons are especially reluctant when they are operating around the spinal cord. Yet patients with spine injury are generally at the highest risk for developing venous thromboembolic (VTE) complications like deep venous thrombosis (DVT) or pulmonary embolism (PE). Is this concern warranted?

Surgeons at the Presley Trauma Center in Memphis examined this issue by performing a retrospective review of six years worth of patients who underwent spine stabilization surgery. They specifically looked at administration of any kind of preop prophylactic anticoagulant, and the most feared complications of bleeding complications and postop VTE.

Here are the factoids:

  • A total of 705 patients were reviewed, with roughly half receiving at least one preop prophylactic dose and the other half receiving none
  • There were 447 C-spine, 231 T-spine, and 132 L-spine operations, performed an average of 4 days after admission
  • Overall, bleeding complications occurred in 2.6% and VTE in 2.8%
  • Patients with VTE were more severely injured (ISS 27 vs 18)
  • Those who received at least half of their possible prophylactic doses had a significantly lower PE rate (0.4% vs 2.2%) but no significant difference in DVT or bleeding complications

Bottom line: So what to make of this? It’s a relatively small, retrospective study, and there is no power analysis. Furthermore, this hospital does not perform routine DVT screening, so that component of VTE may be underestimated, rendering the conclusions invalid.

However, the information on bleeding complications is more interesting, since this is much more reliably diagnosed using an eyeball check under the dressing. So maybe we (meaning our neurosurgeons and orthopedic spine surgeons) need to worry less about preop prophylactic VTE drugs. But we still need better research about whether any of this actually makes a dent in VTE and mortality from PE. To be continued.

Reference: Early chemoprophylaxis is associated with decreased venous thromboembolism risk without concomitant increase in intraspinal hematoma expansion after traumatic spinal cord injury. J Trauma 83(6):1108-1113, 2017.